Soldiers are told to shoot demonstrators on sight

Thousands of Libyans today vowed to defy a "shoot on sight" warning to anyone who joins a mass demonstration against Colonel Muammar Gaddafi's regime.

Pro-democracy protesters in Tripoli called for a rally in the central Green Square after Friday prayers in a challenge to the tyrant's authority.

But as the rebels took the fight to the regime and encroached ever closer on the capital, Gaddafi appeared to dig in to make his last stand. He flooded the city with soldiers, tanks and other armoured vehicles took up positions, while helicopter gunships whirred overhead.

Gaddafi's heir apparent, Saif, today vowed his family would "live and die in Libya" and not go willingly.

Thirty miles from Tripoli, troops opened fire with anti-aircraft guns and other heavy weapons on demonstrators holed up in a mosque at Al-Zawiyah. Local doctors estimated that about 100 people had died already.

There were also clashes in Misrata, 150 miles east of Tripoli, where mortars and rocket-propelled grenades were used on protesters near the airport. Skirmishes have also been reported in the towns of Sabha and Sabratha, near Tripoli.

Much of the east of the country, including the second city of Benghazi, is now in the control of Gaddafi's opponents.

The European Union's foreign policy chief, Catherine Ashton, said that the bloc needs to consider sanctions such as travel restrictions and an asset freeze against Libya to help end the violence.

Nato's main decision-making body was meeting today to consider the deteriorating situation, although secretary-general Anders Fogh Rasmussen has said the alliance has no intention of intervening.